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Arte-miy333 [17]
3 years ago
6

Why do we believe that most of the mass of the milky way is in the form of dark matter?

Physics
1 answer:
Nataliya [291]3 years ago
7 0
<h2>Answer:</h2>

Dark matter is a type of matter, whose composition is unknown and which corresponds to 80% of the matter in the universe. Its name refers to the fact it does not emit or interact with any type of electromagnetic radiation, being completely transparent throughout the electromagnetic spectrum.

However, it interacts with the known matter through <u>gravity</u>.

In this sense, it is believed that the Milky Way has 90% dark matter and only 10% ordinary matter (known matter). Because, like gravity, dark matter can not be observed directly, however its existence is inferred through the movement of the stars and the cosmic dust within the galaxy.

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You must exert a force of 4.5 N on a book to slide it across a table. If you do 2.7J
hoa [83]

Answer: 0.6m

Explanation:

Given that:

force = 4.5 N

Work done = 2.7J

Distance moved by the book = ?

Since work is done when force is applied on an object over a distance, apply the formula:

work = force x distance

2.7J = 4.5N x distance

Distance = (2.7J / 4.5N)

Distance = 0.6 m

Thus, the book was moved 0.6 metres far

3 0
3 years ago
What may be a serious side effect of anti-depressants specific in adolescents?
Klio2033 [76]

I think its suicidal ideation......

I think

3 0
3 years ago
A ray of red light in air is incident at an angle of 30. on a
Vlad [161]

Answer:

20 degrees.

Explanation:

From Snell’s law of refraction:

sinθ1•n1 = sinθ2•n2

where θ1 is the incidence angle, θ2 is the refraction angle, n1 is the refraction index of light in medium1, and n2 is the refraction index for virgin olive oil. The incidence angle of the red light is θ1 = 30 degrees.

The red light is in air as medium1, so n1 (air) = 1.00029

So, to find θ2, the refracted angle:

sinθ1•1.00029 = sinθ2•1.464

sin(30)•1.00029 / 1.464 = sinθ2

0.5•1.00029 / 1.464 = sinθ2

sinθ2 = 0.3416291

θ2 = arcsin(0.3416291)

θ2 = 19.976 degrees

To the nearest degree,

θ2 = 20 degrees.

8 0
3 years ago
Observe the given figure and find the the gravitational force between m1 and m2.​
Leno4ka [110]

Answer:

The gravitational force between m₁ and m₂, is approximately 1.06789 × 10⁻⁶ N

Explanation:

The details of the given masses having gravitational attractive force between them are;

m₁ = 20 kg, r₁ = 10 cm = 0.1 m, m₂ = 50 kg, and r₂ = 15 cm = 0.15 m

The gravitational force between m₁ and m₂ is given by Newton's Law of gravitation as follows;

F =G \cdot \dfrac{m_{1} \cdot m_{2}}{r^{2}}

Where;

F = The gravitational force between m₁ and m₂

G = The universal gravitational constant = 6.67430 × 10⁻¹¹ N·m²/kg²

r₂ = 0.1 m + 0.15 m = 0.25 m

Therefore, we have;

F = 6.67430 \times 10^{-11} \ N \cdot m^2/kg \times \dfrac{20 \ kg\times 50 \ kg}{(0.1 \ m+ 0.15 \ m)^{2}} \approx 1.06789 \times 10^{-6} \ N

The gravitational force between m₁ and m₂, F ≈ 1.06789 × 10⁻⁶ N

8 0
2 years ago
1.Which statement is true when two objects are 20 miles apart but one is much bigger?
Paha777 [63]

1. C.  Gravitational attraction exists between the two objects.

Explanation:

Gravitational attraction is always exerted between two objects which have mass, and its magnitude is given by:

F=G\frac{m_1 m_2}{r^2}

where G is the gravitational constant, m1 and m2 the masses of the two objects, and r the separation between them. Since the two objects have for sure non-zero masses m1 and m2, even if they are 20 miles apart, the value of the gravitational attraction F is non-zero, so the correct answer is C.


2. D.  Two atoms come together to form a molecule.

Explanation:

this outcome is actually caused by the electrostatic forces between the two atoms, not by gravitational force. In fact, gravitational force becomes relevant only when the masses of the two objects involved are large enough: this is the case for planets, stars, galaxies, and objects in the universe. However, two atoms have very small masses, so the gravitational force between them is really negligible. On this smaller scales, the electrostatic force is much stronger than the gravitational force, so the electrostatic force is the real responsible for the formation of bonds between atoms.

7 0
3 years ago
Read 2 more answers
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